WASHINGTON (AP) _ America's workforce registered the best productivity gain in nearly five years over the summer and early fall, laying the groundwork for a rising standard of living.

Non-farm business productivity _ output per hour worked _ grew at a seasonally adjusted annual rate of 4.1 percent in the third quarter, the Labor Department said today.

That was revised down from an estimate of 4.5 percent last month. Still, it was the largest gain since the final three months of 1992.

Productivity increased a healthy 2.4 percent in the second quarter and a more moderate 1.4 percent in the first.

Analysts say such robust productivity is unusual so late in an economic expansion. It's been more than six years since the end of the 1990-91 recession.

Improving productivity is part of the explanation for why economic growth has been so strong and simultaneously inflation has sunk to a three-decade low in 1997. Fast productivity growth means corporations can hold the line on prices while earning increased profits and paying higher wages.